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We go back to the original Superbike engines of the 1970s to see where they began and how they have evolved into the powerhouses we have now. Join us!
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We go back to the original Superbike engines of the 1970s to see where they began and how they have evolved into the powerhouses we have now. Join us!
Find us on Patreon! https://www.patreon.com/cw/CycleWorldPodcast
Become a Channel Partner: https://octanemedia.co/home/become-an-advertiser/
Listen on Spotify: https://open.spotify.com/show/6CLI74xvMBFLDOC1tQaCOQ
Read more from Cycle World: https://www.cycleworld.com/
Buy Cycle World Merch: https://teespring.com/stores/cycleworld
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SportsTranscript
00:00:00Welcome subscribers to the Psycho World podcast. We appreciate you being here.
00:00:04I'm Mark Hoyer, the editor, and I'm with Kevin Cameron, our tech editor.
00:00:10We just had a vigorous off-camera blabbermouth about Ford pickup trucks and Triumph TR6
00:00:19restorations and pancake batter coming out of the oil tank. It was all great. Maybe those
00:00:24would be some kind of podcast in the future, but on this one, we're going to talk about
00:00:28the evolution of the superbike engine, and we're going to use the Kawasaki Z1, the old Z1,
00:00:34a la Rob Muzzy. And then, so that was the superbike engine making 150 horse, pretty good,
00:00:41but horsepower per pound was kind of high. We'll talk about that. And then into modern
00:00:46superbike engines. And what are the differences? Why is it that, you know, essentially a very similar
00:00:52displacement? What are the changes that really have netted our spectacular increase in net horsepower,
00:01:00gross net, whatever, and then specific horsepower per pound? Why is it so much better? There's a lot
00:01:06to it, as you might imagine. And I know someone who might've thought about this, Kevin.
00:01:12Uh-oh. Well, when the Z1 came out in 73, it was the best of current four-stroke motorcycle technology.
00:01:31It was a two-valve with double overhead cams, unlike Honda's CB750, which had single overhead cam SOHC
00:01:43plus rocker arms. But it was a curious mixture. It had a roller crank. The Z1 had a roller crank
00:01:53that was all pressed together with one-piece rods, no rod caps, no cap bolts. But on the camshafts,
00:02:03it had plane bearings with replaceable inserts, just like it was two little miniature crankshafts
00:02:09up there in terms of concept, plane bearings. And the engine was air-cooled, and it had carburetors
00:02:20on it. And the problem with Z1 seen in retrospect is that it was 1960s technology in tires, chassis,
00:02:35and suspension, powered by two Triumph 650 engines. And when, at least on one occasion, when a Japanese
00:02:47engineer was asked, why was this motorcycle not better in these respects, chassis and suspension,
00:02:57he said, you have 60 mile per hour speed limit in your country, 65, whatever, and therefore,
00:03:06no need for no need for fassy stuff. Did he think that we obey the laws? The laws are a
00:03:18suggestion,
00:03:19surely. That's what you see on the interstates.
00:03:24I wonder, did they also consider that the Z1 would become like the durable foundation of drag racing
00:03:33for a period of time? Right. I mean, I think that's one of the things about Kawasaki's relationship
00:03:39with the U.S. market is that it kind of evolved into a performance partnership. We talked about
00:03:44the Z1 on a podcast. You can find that on YouTube or here on Patreon. But it was really, you
00:03:50know,
00:03:51the Z1TC where they turbocharged it in the American market. It was a very strong American enthusiast-based
00:03:58working with Japanese engineering and evolving together as a partnership in the American market.
00:04:05So, but yeah, we, surely we were all obeying the speed limit, Kevin, with our big horsepower. I mean,
00:04:15what a, what a bomb to drop on the U.S. for a four-stroke. Yes.
00:04:19I have to, well, one more thing. I know it's another aside, but that's what we live for. It's what
00:04:24I live for.
00:04:25That in fact, Kawasaki was thinking about emissions and economy when they dropped the Z1. It was
00:04:33actually in there. I read the press material from Ando's CycleWorld test, and they were actually
00:04:39talking about reducing emissions and having a fuel-efficient, tire-smoking, a double overhead
00:04:48be a monster. All this in heaven, too. Yes. So, it was a two-valve engine, and it had basically,
00:04:59as I said, the best of existing technology, which meant that the combustion chamber and
00:05:06valve angles and so forth were very much like the Norton twins. 58 degrees, more or less,
00:05:14between the valve stems. So, it did not have a deep combustion chamber like a Sportster or a Triumph 650
00:05:24early type. A real, you know, a bird bath for big drinkers with a lot of surface area to heat
00:05:33the thing
00:05:34and make it very hot. Well, this was an atmospheric engine. It was not supercharged. So, when Rob Muzzy and
00:05:48company got hold of it, they were able to fill the cylinders quite well, up to a general limit.
00:05:59And three years, three or four years after the Z1 hit the market, the AMA had to create a class
00:06:08for
00:06:09these new big-inch motorcycles. Superbike. And then everybody quickly found out that having,
00:06:22doubling the power and not updating chassis, tires, and suspension was exciting, to say the least.
00:06:33In 1977, I stood at Riverside, the old Riverside track carousel. Every superbike that came through
00:06:42there, it was weaving. And weave is a two to three cycle per second, complicated, coupled, roll, pitch,
00:06:56yaw, motion. I believe that's the same frequency as nausea in my book. Yes. And people found out that
00:07:08they had to be able to make changes. Well, somebody had talked the right talk to the AMA because the
00:07:18book said front fork may be modified or replaced. Swing arm may be modified or replaced. Some people were
00:07:30bracing the swing arm so that the rear tire in between the swing arm beams was not able to do
00:07:38too much of
00:07:39this. Because what you don't want on a high-speed motorcycle is a direction of motion that is a result
00:07:51of two wheels, that of the operator and that of the motorcycle's problems. And this was the theme of
00:08:02the US sit-up 1,000cc superbike for its whole life. They were constantly working to improve chassis
00:08:12performance and to be able to get more and more power on the ground. Now, making power wasn't really
00:08:24a problem. They were making 135 horsepower pretty soon. But it wasn't doing them any good because they
00:08:32couldn't get it to the ground, which is why the first superbike championship was won by a BMW flat
00:08:42twin. What? Exactly right. 50 years ago, the door was open because of what Kevin said, they couldn't
00:08:50get the power to the ground. And they were pretty heavy, like the Z1s and that elk were a pretty
00:08:55heavy
00:08:55motorcycle compared to the BMW, which was probably a hundred plus pounds lighter than the equivalent
00:09:03Kawasaki. And Udo Giedel and company with Butler and Smith, particularly on the later 1,000cc, the R90s
00:09:11based versions. Udo was clever and he was really getting a tremendous amount of power out of those
00:09:18things. And they were moving the engines and the chassis. In the 90s. In the 90s for power. Yeah.
00:09:24Yeah. So this underlined the great rule of pavement racing, which is, it's not how much power you have,
00:09:34it's how much you can use. And if the moment you hit the gas, it starts to shake, rattle, and
00:09:44roll,
00:09:44unless you're Yvon Duhamel, who was a man of purpose and courage. When it started to shake,
00:09:55rattle, and roll, and it looked really frightening to us at trackside, he would come in from practice
00:10:03and say, I think it's maybe a little better now. Well, that was an era. But the important
00:10:14thing about that era was that it created a horsepower race. It created a performance race.
00:10:23Because we have to remember that when Interceptor 750 was brought to the market by Honda,
00:10:32people began to buy motorcycles based not only on quarter mile time and peak power,
00:10:38but handling. That was yet to come during the sit-up era. But Rob Muzzy said his top engine is
00:10:51152 or
00:10:54whatever horsepower version. When it gets to 11, he said things start to go bad in a hurry.
00:11:04Now, they had already got through a spate of breaking connecting rods near the small end,
00:11:11so that most of the length of the connecting rod was still on the crank pin with three strong running
00:11:18cylinders powering it as a jackhammer to poke holes in the crankcase. Oh, peekaboo!
00:11:25And engines coming into the pit area making that awful clattering noise and just broken to pieces.
00:11:40Well, the Japanese began to plan how to fix this. Oh, 65 mile per hour speed limit.
00:11:49As it says in the song, well, that was just a lie. So they began to figure out what to
00:11:59do
00:12:00in future. And one of the things that they had to do right away was consider
00:12:09crankshafts who don't slip at the joints and to consider valve systems that don't float the valves
00:12:21at the speed you'd like to be making reliable power. Now, it's possible in drag racing, you just go up
00:12:30in
00:12:30with the spring. And if the tappets start to turn purple, you run oil feeds in there. It only has
00:12:39to
00:12:39run for a few seconds. But if you're going to go 50 miles, which those early superbike races were,
00:12:47another important consideration by the AMA, they were made to understand, if you don't make these
00:12:55races that short, somebody, there might come a day when nobody would finish. Because these things have
00:13:02got little bitty fuses on them. I would like to give credit to John Ulrich and Steve McLaughlin,
00:13:09who wrote the rules that the AMA adopted. Because they sat around two racers, Steve McLaughlin,
00:13:15famous superbike racer, John Ulrich, a good racer in his own right, who's run a race team
00:13:20for 60 years now or more, you know, out there, still at it. And they sat in John McLaughlin's
00:13:30empty apartment. His girlfriend or wife had left and taken the furniture. And Ulrich took his wife,
00:13:36Trudy, on their first date to go write superbike rules. How romantic, in an empty apartment on the
00:13:42floor with a typewriter. But they, they were both practical people and they were racers. And
00:13:49they said, well, you know, we, we, everyone wants to race these, we can buy these.
00:13:55We have to make the fork, we have to make them into race bikes as best as we can do
00:14:00so with the rules.
00:14:02So that we have some kind of playing field to play on. But it was replace this, replace that,
00:14:08reposition the shocks. And like BMW, Udo Giedel, like that's a twin shock motorcycle that they're
00:14:14near vertical. And Udo replaced, he moved one of the shocks to the shelf and repositioned the other
00:14:22shock as a monoshock on some of the bikes. And so there was a lot of creativity. But as Kevin
00:14:29said,
00:14:29that was the evolution of handling that led to the bikes in the eighties that actually had
00:14:34a stiff chassis and had working suspension. And it's all because we started making a lot of power.
00:14:40We figured out how to make a lot of power. And that just laid bare all the other problems.
00:14:47Yep. Just so plainly.
00:14:50Because a motorcycle is like layers of problems. You peel one off. Oh, what? Oh, no.
00:14:57And it goes on like that forever because there's no satisfied rider. Nobody comes into the pits and
00:15:04says, that's great. Don't touch anything. Yeah. Well, you don't expect to hear that.
00:15:10Well, we go faster. We load it heavier and then we get more. Suddenly we have chatter,
00:15:15like the tires get better and it's chatter. What's going on? It's like the old Honda story that you
00:15:21always tell about the new Dunlop came out with some spectacular new DOT race tire and they put it
00:15:30on the existing Honda 600 of the eighties, nineties, whatever it was. And it induced chatter. And the
00:15:36first step was, oh, no, I think we can solve this problem by going back to the old tire. Like,
00:15:41no,
00:15:41we can't do that. In fact, we have to go faster if we're going to race. That's the point.
00:15:48Yes. Mr. Yoshida, speaking in 1973 in Atlanta, he said, if riders go slower, then no more trouble
00:15:59again. Yeah. Well, like your Cal Carruthers quote, I think we're going to be spending as much time on
00:16:05chassis and suspension as we have on engines in the near future. Maybe more. Maybe more. Yeah.
00:16:11Yeah. That was at breakfast after Pocono. Great stuff. Yeah. It's I, sometimes I get out my
00:16:20notebooks. I've got stacks of them. I have hundreds and I start reading this stuff and I think,
00:16:26oh, I forgot all this stuff. This is great. And the information that was available,
00:16:35you could just talk to people. You know, it wasn't like you were in a high security building
00:16:41and everyone's lips were sealed. Well, it's so top secret in MotoGP now. It's very hard to get
00:16:48actual information. I think the engineers want to tell you, but they can't. Yeah. They would love to
00:16:54have a conversation about all of these interesting things that they're doing because it's interesting.
00:16:58Because it's so cool. And they have no one to talk to about it. Right.
00:17:04One of these days we'll get it out of them. That's it. A couple of drugs. You may name it.
00:17:10Well, you know, it was cool. You were just talking about reading your notebooks and like,
00:17:13oh, I forgot that. And we've had more than one comment, Kevin, on the YouTube channel
00:17:19about, well, I would say Kevin Cameron's forgotten more than I'll ever know about motorcycles,
00:17:23but I don't think he's forgotten anything. Oh dear.
00:17:26Here's the proof. Yeah, it's the truth. We have to admit. Okay. Well,
00:17:33they had to get rid of the rolling element crankshaft. Now, it is true that when Suzuki built the GS,
00:17:42it had a roller crank. And it was an improvement in the chassis department and in certain other respects.
00:17:50And it was worthy competition for the Z1. And it was clear that this was not going to end.
00:17:57No one was going to say, okay, you're the king. We're serfs.
00:18:03So they're all striving for, well, here's the thing. If people set to work trying to fill a cylinder,
00:18:14it doesn't matter if you have a two valve or a four valve or a five valve, eventually you hit
00:18:20a certain
00:18:23degree of cylinder overfilling. And that's it. The atmosphere doesn't push anymore into the
00:18:31cylinder, even when assisted with all sorts of intake and exhaust waves bouncing around.
00:18:36So as long as we're breathing this atmosphere, that's the upper limit for an unsupercharged engine.
00:18:44That being the case, the quickest way to increase horsepower is to increase RPM because that
00:18:54performs the power producing cycle more often. Each little pellet of power, if you can stack up more of
00:19:03them, you have a remarkably strong force acting on the rear wheel at a high speed. So that meant
00:19:13two valves were going to be a problem and two valves persisted into the super sport.
00:19:21You're a Seca 550 or something. It wasn't that a two valve.
00:19:27They let the two valves run out before replacing them in with a, an updated model.
00:19:34But the thing was to switch from two valves to four. And why would you do that? Well, it looks
00:19:44like
00:19:46um, it's going to give you a lot more area because you've got two intakes, even though they're smaller,
00:19:52the total intake valve head area is greater than the single valve, but that's not it really. What is it
00:20:02is the fact that when you scale a valve down, it loses weight faster than it loses area.
00:20:11And that's the so-called squared cubed rule. The weight is proportion, proportional to the density,
00:20:19uh, proportional to the, um, dimension cubed. You know, like a cube is one side cubed.
00:20:34And X times Y times Z is the volume of a cube. So, uh, when you do this with valves,
00:20:43they become lighter faster than they lose, uh, flow area. And that's why Honda adopted four
00:20:54valves per cylinder from 1960 through the classic, uh, Japanese invasion of Grand Prix motorcycle
00:21:02racing, which ended in, um, 67. So at first,
00:21:13people were, were criticizing this. Don't they know that a single valve in a, in a beautifully
00:21:18curved hemi head has a higher flow coefficient than two nasty little valves in a, in a folded
00:21:27piece of paper or something that looks like an army tent and cylinder head growth. That can't work.
00:21:33Everyone knew this since what? 1922. This was the received truth, but it was more important to be
00:21:42able to perform the power producing cycle more frequently. And two intake valves could be much
00:21:48more easily controlled at high RPM than one great big stonking valve.
00:21:56And when, uh, uh, BRM didn't get any satisfaction from their 12,000 RPM V 16 Grand Prix engine,
00:22:08they went to the other extreme and built a standup four with two valves per cylinder, great big valves
00:22:16that broke when they were driven hard enough to keep them from floating. They just broke.
00:22:25So there are problems that you can run into if you say you're one of these people that's determined
00:22:32to prove that two valves are just as good. And there've been a few of those. Um, why not go
00:22:40the easy
00:22:41way with four valves per cylinder? And that's the way they went with the second generation of superbarks.
00:22:51And they tried to combine that with air cooling and had some trouble. Everybody does. For example,
00:23:00Honda, when they built their two 50 inline four, uh, which initially rev to like 13 and 13, five.
00:23:10Uh, they had to give each cylinder a cast iron skull around which the cylinder head was cast.
00:23:21And that cast iron skull, uh, didn't have any valve seat rings to loosen or move in undesired directions.
00:23:33It worked.
00:23:35That's an old, uh, old idea too. The, the skull being cast into a combustion chamber dates way back. I
00:23:41mean,
00:23:41that was a solution that was used by many, many makers in the old days because for that same very
00:23:46problem of like, you know, valve seats raining down.
00:23:53Can't have that.
00:23:54No, sir, it makes a awful tinkling noise bothers people and wrecks engines. So, uh, they had to
00:24:05develop, uh, double overhead cam engines with four valves per cylinder. And the problem with
00:24:15cooling air cooling of four valves per cylinder was big.
00:24:21And if you lift up a seven 50 cylinder head from say, um,
00:24:30an early, uh, liquid cooled Yamaha, it weighs practically nothing. It's just so light.
00:24:37Pick up one from the last of the Suzuki four valve air cooled engines. It just weighs a ton.
00:24:44Even the GPZ five 50, that was a two valve double overhead cam, like 82.
00:24:51Boat anchor of a cylinder head, even with two valves. I mean, they're just,
00:24:54you got to put the metal in there. That's for the, what do you call that? That's the bank
00:24:57for the heat sink for the acceleration down the straight to give the heat somewhere to go.
00:25:02That doesn't melt everything down. And then you roll off and it's like, thank goodness.
00:25:06Oh, we stopped pouring it in so hard. And, uh, when, when, uh, Dick O'Brien was sort of
00:25:17standing behind, um, Pete Zylstra, as he drew the, um, aluminum XR cylinder head,
00:25:27he said, uh, 750. Yeah. Uh, he said, I want an inch of goddamn aluminum on that goddamn cylinder head.
00:25:38And Zylstra knew why he wanted it. He wanted it so that instead of the cylinder head heating up like
00:25:47crazy as the bike accelerated down each straightaway, that there would be a mass of aluminum there that
00:25:55could absorb the heat and not get as hot. You know, if you're going to play a blow torch on
00:26:02a
00:26:02piece of metal for 10 seconds and then pick the metal up, oh, that hurts. You want the biggest piece
00:26:10of metal. That's the, that's the reason. And that's why those air-cooled four valve cylinder heads are so
00:26:17heavy. That was the way that they could keep the valve seat rings in them and make a workable proposition.
00:26:26Well, now another problem is air-cooled engines and compression ratio can be a big problem
00:26:34because the air-cooled engines operating temperature goes up in the summer and goes
00:26:39down in the fall. And if you still ride the winter and this,
00:26:48this is bad because the compression ratio has to be planned for the worst case.
00:26:57Um, you know, two rider and passenger on the bike climbing,
00:27:04summer temperature, heavy hand on the throttle, even if the RPM is a bit low,
00:27:11maybe lugging, definitely knocking.
00:27:17And you can't have that because when an engine detonates chronically, the
00:27:25sonic combustion waves of detonation nibble at the edges of the piston until the top ring is exposed.
00:27:34Now we hope that you'll hear that and say, damn thing's detonating. I gotta, I gotta fix this.
00:27:40Ease up. Let's throw some base gaskets on these.
00:27:43Ease up, throw some base gaskets on these.
00:27:45Yeah. Yeah.
00:27:46Yeah. More base gaskets to blow out. So, uh, you will notice that the great air-cooled, uh,
00:27:55superbike engines have compression somewhere between 8.5 and 10.
00:28:01And yes, you could run a higher compression than that in a drag racer, but you're only running for seconds.
00:28:08Uh, here they're building a product that has to go out from the dealer under warranty and they
00:28:14don't want to lose their shirt buying parts for engines that chronically detonate. So they'll
00:28:21reduce the compression ratio. Well, this is a terrible thing because
00:28:28the rule of thumb and it's a very rough one says peak combustion pressure is 100 times the compression
00:28:37ratio. So which would you rather have 850 PSI or 1300 PSI pushing down on your pistons?
00:28:50It's a question that answers itself. So that was another push toward liquid cooling. The first
00:28:59push came from the problem of keeping valve seat rings in the head in an air-cooled engine.
00:29:10And eventually something had to give. Now,
00:29:18uh, product planning people knew that riders love fins. It makes engines look mysterious.
00:29:25When my dad took me to New York from Boston on the Convair 240, I think, uh,
00:29:35would be 19, 1948.
00:29:40Beautiful aircraft.
00:29:41I looked in the nacelle and I saw these fins with these curving,
00:29:49just beautiful masses of cooling fins. And I've loved those giant engines ever since that time.
00:29:57Well, those are, those are pretty neat. I, I, I want to add in my little Convair, uh,
00:30:02note here is that there's a Convair at the airport. Uh, we go,
00:30:06my son and I go every Saturday and it's full of warbirds. We go out to Chino and, um,
00:30:11we work on a Taylor craft and some other stuff. He flies and we do a few of these things,
00:30:16but they
00:30:16have a Convair on the ramp there, uh, as parked across from the business where we are sort of
00:30:22helping out as in this nonprofit and it's a Convair and the cowlings open, the nacelles open like the
00:30:29petals of a flower. Oh, I mean, just, you know, in the old days you're like taking off and then
00:30:36there's a crane and like, no, this thing's in service, man. We got it. We got to get her in,
00:30:40get her out. We got to make some, make some money here, you know? And it, they, they open this
00:30:44way
00:30:45and this way, this, like the four petals of a flower. And then you have that beautiful, uh,
00:30:49radial sitting there waiting for you to caress its inner workings.
00:30:54And so people love fins. It makes engines look
00:30:59frankly mysterious and mystery is an important element in beauty.
00:31:05Beauty keeps us mesmerized and that's one element of beauty,
00:31:12but the pressure is in the direction of liquid cooling. Now, Honda had a problem with two products.
00:31:20The first one was the, um, Goldwing, which was a flat four, which meant that if it were air cooled,
00:31:30the rear pair of cylinders would be in quotes, cooled by hot air that had just cooled the front
00:31:38cylinders. That will not work. It cannot work.
00:31:44Unless you're, you know, just putting around. Of course it'll run.
00:31:50But if you want to get power from it, like steady cruising at 75 miles an hour,
00:31:56which was the rear cylinders are going to be very unhappy.
00:32:01First liquid cold honor folks.
00:32:03Yeah.
00:32:05So, and it was a sort of a puzzle that motorcycle when it arrived, because people couldn't
00:32:10work out what it was, what is a super bike? Is it a touring?
00:32:16Well, look at the Goldwing now. What a dynasty it formed.
00:32:19It did. It did. It led to a great dynasty. And what I never tire of repeating and I'm sure
00:32:27you've
00:32:27heard me say it before is that the current Goldwing engine gives 80% of peak torque at 850 RPM.
00:32:40Now, is that a broad torque curve? I would say so.
00:32:45It's so good.
00:32:47And of course it was converted to four valves. The Harley is converted to four valves.
00:32:53Everything converts to four valves because it allows you to broaden the torque curve.
00:33:00Because with two valves, the way you can boost power is by keeping the intake open longer after bottom
00:33:07center so that the air, which the intake flow, which is whipping in there at hundreds of feet per
00:33:13second, are you going to put the stopper back in the hole at bottom center when it's just
00:33:19yearning to get in that cylinder? No, you're going to keep it open.
00:33:22But the problem comes when you're operating the engine at lower than peak torque RPM.
00:33:30What happens then is that the air is moving much more slowly. When the piston rises on compression,
00:33:36it just pushes it back out of the cylinder, which is why you get the so-called light switch power
00:33:42band of a highly tuned engine. You turn on the throttle, the thing accelerates in a sort of
00:33:50half-hearted, did you want something away? Yes. And then you get to a point where you are thrown back
00:34:00in your seat and your arms are stretched to full length as the power finally hits.
00:34:09So that's not what you want in a tour bike. And it turns out it's not what you want in
00:34:14a race bike
00:34:15either. You want power available at all RPM and controllable, predictable power. All motorcyclists
00:34:25agree that even though it's exciting to ride a light switch bike, it isn't good.
00:34:33Yeah. You want the tool. That's the thing. You want the tool. You want something, especially if,
00:34:38you know, you're going to race for 50 miles or an hour, 45 minutes at full, you know, like,
00:34:46how bad do you want to wrestle with something that is moderately unpredictable or goes,
00:34:51doubles its torque in 200 RPM?
00:34:53Yes. That's why two strokes were remarkably powerful for their weight, but they were bad
00:35:02racing engines in the sense that it was the rider had to give more attention to the engine,
00:35:09which meant giving less attention to the racing. It was a tough, it was a tough play because I love
00:35:17those things. I worked with two strokes for 20 years. Um, society has dictated otherwise. So
00:35:29anyway, Honda made that thing liquid cooled, the flat four. And the next thing was, uh, interceptor
00:35:38and saber, which were V force. And they too had the problem of how are we going if we make
00:35:46an
00:35:47air cool, how are we going to cool the rear cylinders with hot air off the front cylinders?
00:35:54Well, we could duct it. We could bring in air from the side. Do you want ducts on your beautiful
00:36:00motor?
00:36:02Or do you want to see the motor? Harley people at least like to see the motor. I like to
00:36:08see motor.
00:36:10And you know, a little quick aside about front cylinders and rear cylinders,
00:36:14Harley Davidson V twin, right? You have a cylinder in the back, which is usually fine if you're just
00:36:20chuffing down and you're not, you know, you don't have 14 to one compression and all the things that
00:36:24Kevin's talked about chuffing down or putting out. Yeah. But if, if you're liquid cooling as Harley
00:36:32does with a lot of its touring bikes, they now run the water from the radiator to the rear cylinder.
00:36:38First, the cool water goes into the rear, normalizing the temperature through the whole engine because
00:36:43it's hotter. And that was a strategy on the most recent, uh, twin that they've reduced the one that's
00:36:49in the baggers. Now the, the latest big twin, the one that gets, uh, the radiator is running in the
00:36:54rear
00:36:55cylinder first for the very same reasons that talk, Kevin's talking about air cooling and liquid cooling
00:36:59sabers. Same deal, but, uh, continuous evolution. Yeah. So now we've got a capable crankshaft,
00:37:09one piece forging in plain bearings, which contrary to one's intuition are entirely competitive with
00:37:19rolling bearings, uh, as to friction and are infinitely longer lasting.
00:37:30So we've taken care of the crankshaft. We've taken care of the valve train.
00:37:36Now we've water cooled the engine. So the compression ratio can go up. It helps at every RPM.
00:37:46The compression ratio is just a geometric thing. It is the ratio of the volume above the piston when
00:37:52it's at top center to the volume above the piston when it's at bottom center.
00:37:58You're squeezing the mixture tighter. So it goes up in pressure higher.
00:38:06And man, it makes the exhaust gas cooler because you're taking more energy and putting it on the
00:38:14piston, which means there's less leftover to make the exhaust hot.
00:38:20Yeah. We've got production bikes running 14 to one, 13, seven now.
00:38:24Yeah. And you know, in the old days, that is made possible. That is made possible by the next big
00:38:30difference, which was that, uh, product planning and design managers are saying
00:38:40emissions regulations are coming. What are we going to do about it?
00:38:46Well, the first thing they had to do was to lean down the carburetors that were still in production.
00:38:51And that was a catastrophe. That was the era of stutter and stall.
00:38:58You hit the start button, it fires, and then it quits. You hit the start button again.
00:39:04Full-blooded, we always used to say.
00:39:06It just goes on like that.
00:39:09And this is also why, uh, at Daytona, the PA system was always barking out,
00:39:18well, Mark Dobeck, please go to garage 28.
00:39:22Because he had all the needles and those tiny little spacer washers and clips. And he had experience
00:39:32so that he could get your engine to make the power it was designed to have without stuttering and stalling.
00:39:42And that couldn't last. That just wasn't satisfactory. It was going to be a major, uh, reason not to buy
00:39:51a motorcycle,
00:39:51which is not in the spirit of this enterprise. So fuel injection had to come and ignition timing controlled by
00:40:06a computer.
00:40:08There were few efforts to make, uh, automotive type, um, air meter, fuel injection systems for bikes.
00:40:19As the wind blows into the intake pipes, it pushes a door. And the angle of the door is
00:40:28in some way related to the volume of air that's passing.
00:40:31Yeah. Mass air flow. They were also heated wires. They would run a heated wire and then
00:40:36they would alter the voltage as the air blew over the wire. And then they would calculate from that.
00:40:42So an MAF mass air flow sensor type, and then there's.
00:40:46Well, this was all very well. Uh, but
00:40:52motorcycling went a different way. They went the map direction and
00:40:59or speed density in alpha and is RPM and alpha is throttle angle. And what they did was they ran
00:41:09engines on the dyno and they found out what gave ideal power or planned power at all RPM and throttle
00:41:19angles. And they stored that in a map. And on top of that, they added, uh, sensors, which were like
00:41:28having
00:41:29a race team technician, smallified to fit into your ECU, smallified, constantly, constantly,
00:41:41and ideally altering your mixture to go along with changes in atmospheric pressure and temperature
00:41:47or altitude. Oh, we're crossing the Rocky mountains.
00:41:59So, uh, and it's, it's absolute manifold. Absolute pressure is one of those that they're using. So it, you
00:42:06know, you don't even necessarily need to read atmospheric. You're just reading what's happening
00:42:11in the intake manifold. Cause that's the number that matters. And then you have a throttle
00:42:15position sensor and they just, you know, they can sit in there and your little computer box has
00:42:19little chips and the memories and, and, uh, for example, in, in. Dobeck was the founder of Dinojet.
00:42:28That's who Kevin just mentioned. And he had the Dino and he had the jet kits. And so, wow, this
00:42:35was a
00:42:35really big progression and we could tune in and we could find out what's making the power and do all
00:42:40this stuff. And then Dinojet did what EFI did. And we made boxes that were adding or subtracting from
00:42:47the table that was stored in the motorcycle. So I found out if it has a zero, the multiplication
00:42:52factor doesn't work. If it says zero, you can't change it. If there's a one, is that changeable?
00:42:58I'm not sure. But, um, yeah, it was interesting. So it doesn't matter what you multiply zero times.
00:43:06Right. The answer is zero. Right. So, uh, I was trying to fix an MV Augusta and I was on
00:43:13the phone
00:43:13with the Rallo Ferracci. I had an MV Augusta F4 and it was a pretty good running bike, but it
00:43:21made,
00:43:21it just made awful. And this was, this was like circa 2003 maybe, or 2001. So here's this F4 750
00:43:31and inline four liquid, cool, beautiful MV Brutale. It was a Brutale and it was making,
00:43:39I think like 113 horsepower, but it was getting like 27 miles per gallon. And I did every, I put
00:43:48a
00:43:48box on it. I put a dino jet box on it and I tried a lean cruise and I tried
00:43:52all these different
00:43:53schemes and I called the Rallo and I'm like, Oh, Rallo. I said, a GSXR 750 makes 126 horsepower at
00:44:02the rear wheel on our dyno. That's like 10, 10, 12 more horsepower. And it gets 43 miles per gallon.
00:44:08If you just cruise around on it, I'm like this Brutale. I'm like, where does the fuel go? He's like,
00:44:13ah, you know, and he just started telling me about like, well, they did the, this with the
00:44:17primary ratio and you know, yada, yada, yada. And you know, we tried to fix it. We got close. We
00:44:23got,
00:44:23we improved it, but it was never the same, but you could, that's the beauty of having the box is
00:44:28you
00:44:28can, you can mess with your, I don't know. I, I like having a laptop. I love working with jets,
00:44:34but man, what a pain in the ass, right? Getting into a carburetor when you can just plug in
00:44:39and you can just say, okay, let's change the table. Like I worked with a guy who was a great
00:44:43technician at
00:44:43Dynojet. He was actually a leadership. He was like one of the higher ups, incredible motorcycle rider
00:44:49and an incredible technician. And I told him I had put one of these Dynojet boxes on my WR
00:44:55250R dual sport bike. And I'd taken the top off the air box and it had a pipe. And I
00:45:00was like,
00:45:01I thought it would make a little bit more power on the top. And I said, it's, you know,
00:45:04the fueling I think is quite good, but like, what about ignition timing? And that guy goes to my
00:45:08motorcycle in a parking lot in the mountains and plugs in and he's holding his laptop and he one
00:45:14hands the, the spark table. It's like, oh yeah, these are, they're Japanese are really, really,
00:45:19really conservative. Watch this. And he goes, and he highlights all these different grids and he
00:45:23starts kicking it up. He's like super safe still. Like you can, you're going to be fine.
00:45:29Difference like the throttle response. And then the Dyno numbers, uh, it was a couple horsepower just
00:45:34from timing and he did it all on the laptop. It's not, you know, it's not springs and weights in
00:45:38the back in the bad old days or, or fixed ignition timing. Like Kevin dealt with on all these two
00:45:43strokes where you're like, well, let's go with 22. You know, and that's all you had was 22 degrees.
00:45:50It's crazy. Anyways, it was too much on top end and it was far too little, uh, down at 6
00:45:57,000. So
00:45:58it was a nasty, hurtful compromise. I, you might have to go to counseling to deal with something
00:46:08like that. Right. So we have map sensors now and we can, so yes, this is, this is a wonderful
00:46:14thing
00:46:15is that the computer is sitting there, master of all its surveys and the sensors tell it, uh, current
00:46:25conditions are this. And it has so many microseconds before it needs to send instructions to the
00:46:32injector and having the conditions, it then sends this to the lookup table and the lookup
00:46:38table sends back the injector must be open for this many, uh, milliseconds. This is how fuel
00:46:47is doled out. Now it doesn't flow continuously. There's a single regulated pressure in the
00:46:54fuel system, um, which is somewhere around 50 or 60 PSI. Typically. And that is your reference
00:47:03pressure. So the fuel is doled out by how long the injector valve is open duty cycle. Yep.
00:47:15And, uh, so many, uh, microseconds is, is so many tiny, tiny, tiny volumes of fuel and it's all very
00:47:27precise. And at the same time, the lookup table says, Oh, by the way, the ignition timing for this
00:47:33cycle should be this. And that's the timing that it, that it fires at. Yeah. And a closed loop system
00:47:40is,
00:47:40is reading what's happening in the tailpipe. So you're getting a message from an O2 sensor
00:47:45and it's saying like, Oh yeah, you're, you know, we're aiming for emissions. We're aiming for
00:47:49stoichiometric. So we're trying to theoretically burn every molecule of everything, uh, so that the
00:47:56least amount of smoke comes out the tailpipe that we, uh, we're, what are we, we're searching for that
00:48:02theoretical perfection where we just get water and, um, CO2. Carbon dioxide. Yeah. Which, which we
00:48:09don't achieve, but we, we get ever closer as we get smarter and smarter. When you're rich enough to
00:48:15increase the number of molecules beating on the pistons. Speak in my language, Kevin. You will find
00:48:224% CO, please. You're getting 4% carbon monoxide. Well, of course it's poisonous. It's harmful,
00:48:30but you have to remember that's what makes your stakes and roads so big. It's 150 miles an hour
00:48:37behind me, man. Well, there's that too. Yes. I'm sorry. We are leaving it all behind. That's why
00:48:46a friend of mine who grew up near a British air base as a small boy, he saw the English
00:48:54electric
00:48:54lightnings accelerate down the strip with their two engines, one above the other glowing from the
00:49:05afterburner. And then the pilot took away the undercarriage and disappeared vertically.
00:49:13It's reheat. Yes. Reheat. The British call afterburners reheat. I love that reheat. Yes. And that's exactly
00:49:22what it is. There's, there's a lot of unburned oxygen, uh, that passes through a gas turbine. And if
00:49:28you spray more fuel into it, you can make a sort of crude rocket motor. And that's what an afterburner
00:49:36or reheat system is. So, um, I think he paid 9,000 pounds to go to South Africa and have
00:49:47that ride
00:49:48in the privately owned English electric lightning. And I think that that symbolizes one of the
00:49:55ambitions of motorcycles, which is to leave it all behind. Agreed.
00:50:01I used to wish when I was courtship age, that I could have a reverse parachute, which would yank
00:50:10me upward from unpleasant situations. You bought a BSA Bantam instead. Yes, I could, I could drift away
00:50:21serene in mind. So what do we have for a bottom line here? Well, um, Muzzy's 152
00:50:31horsepower translated into world super bikes, making what to 235 horsepower, um, is a, uh, 50%
00:50:44increase in power. And you look at the RPM. Oh, it's a 50% increase in RPM because peak cylinder
00:50:54filling is the same for both. One in one way, there are two intake valves in each cylinder.
00:51:01And in the other way, there's one, but you can do all the wonderful tricks of the tuning
00:51:07trade and fill the cylinders, just pack it in. So we'd be dealing with a virtually identical
00:51:16BMEP. Yes, that's exactly right. Which is the combustion pressure averaged over the stroke
00:51:24with, uh, friction forces and so forth subtracted. So, uh, break, break mean effective pressure.
00:51:32It's a fun, fun little game to play. We use it to try to calculate horsepower of motorcycles
00:51:37that we don't know about that we can't, we can't get numbers for like Harley won't talk about their
00:51:42bagger horsepower. Indian won't talk about their bagger horsepower. MotoGP will not tell you the
00:51:48horsepower of an Aprilia. Aprilia won't tell you. So we have to stand back and say, well,
00:51:54a highly developed racing engine makes 200 PSI. And what does that translate to at a 1000 CC? And
00:52:01you can do the math and Kevin will show you how to do the math. It's pretty fun. And you
00:52:05can,
00:52:05you can don your wizard hat and try to predict what Aprilia is making at the projected RPM.
00:52:12Let's now compare, uh, Muzzy's 152 horsepower with MotoGP's claimed 300 horsepower, two to one.
00:52:25They've doubled the power in 44 years and, uh, they've doubled the RPM because 10,250
00:52:37in Muzzy's engine. And they're saying 20,000 RPM maximum in MotoGP. So again, the, the rule pretty much
00:52:50holds that, uh, horsepower is proportional to RPM in an engine that is well developed in terms of cylinder
00:53:00filling. But there's also the, the, the question of weight. Those sit up.
00:53:09I've been sitting here waiting for you to say that. I was like, when's he going to mention this?
00:53:14Cause we've, yeah. Uh, back in the sit up super bike days, thousand CCs engines weighed pretty much 200 pounds.
00:53:26And, uh, why was that? Well, it turns out this was something that was discovered in the late nineties
00:53:39by, uh, by, uh, English researchers. They're looking at oxygen content of castings.
00:53:49And they found that there was a significant oxygen content, but at the same time, they knew
00:53:55that the solubility of oxygen gas in aluminum is such that if we added together all of the aluminum
00:54:08that's been created by humanity to date, that the correct ratio would be one atom of oxygen
00:54:16to that enormous number, something like 10 to the 35th power, which is a lot.
00:54:23Yeah. Oh, it's a scientific notation. I think we're using that for the gas price signs right
00:54:28now too, by the way. Yes. Cubed. Sorry. Sorry. Carry on.
00:54:34Fourth power. Eighth power. Molecules. Take it away.
00:54:39So where's that oxygen? How does it get into the casting? When they looked at that in detail,
00:54:45they found that what was happening was anytime you make, that you have a molten aluminum exposed
00:54:52to the atmosphere, a thin film of aluminum oxide instantly forms on the surface. The problem occurs
00:55:01when you're pouring the casting. If you have sufficient turbulence, those films of aluminum oxide
00:55:10are entrained in the flowing liquid and carried into the casting where they are trapped until the material has solidified.
00:55:23So this material doesn't stick to aluminum, like aluminum. So what you have is like
00:55:31little pieces of tape throughout the casting that are zones of weakness.
00:55:38It's just like all those streaks of carbon in cast iron. Break on dotted line. Cast iron
00:55:50that is not where the carbon is not spheroidized is brittle.
00:56:00So when they investigated further, they realized that aluminum castings could be a lot stronger,
00:56:08and I mean a lot stronger, approaching forged qualities, if we could get rid of those aluminum oxide films.
00:56:23So they devised methods. There's a lot of different patent stuff that goes into this bottom fill,
00:56:31filling the casting from the bottom fairly slowly so that it isn't all a fountain of liquid aluminum,
00:56:37isn't shooting up out of the surface.
00:56:41I know Yamaha was an early adopter, and they were dubbing that controlled fill, what you were describing,
00:56:49and a vacuum in the mold and, you know, really doing everything they can to keep that entrainment from happening.
00:56:56Yep.
00:56:58The very expensive book now is that Castings book you were citing.
00:57:02It is not cheap, but it's called Castings.
00:57:05I forget the fellow who wrote it, but Kevin's got a copy on the shelf. He's spying.
00:57:10That's right, right there.
00:57:12I gave mine to another person who I thought could use it more.
00:57:16I'd read it and gotten headaches, and I'd read about entrainment, and I'd entrained every bit of
00:57:22casting detail and technology that I could foresee using in my remaining years,
00:57:27and sent it to a friend who lives in the metal world, and he was grateful.
00:57:33A long time, long serving Honda crew chief, Al Ludington, around 2000, I remember him saying,
00:57:47well, this year Yamaha's making all their major castings using this new method,
00:57:55and their bike is 35 pounds lighter than ours.
00:58:01And what this means is that it's possible to make the engine lighter and stronger at the same time.
00:58:10There's a good deal of gain in this process, and there's all sorts of stuff in the book about how
00:58:18the material can become stratified so that when you heat it or you try to heat treat it,
00:58:26that it exfoliates it. Layers rise up and pop off. It's disgusting.
00:58:33It sounds like baklava. Not that baklava is disgusting. It's just that it's in lovely layers.
00:58:45So this casting problem of having to use a lot of metal has been ameliorated. It has been made better.
00:58:56It
00:58:58so the result is that Ducati's 1100 cc v4 making, what is it, 228 horsepower with...
00:59:07Well, if you throw the pipe and the special oil at it, it's close to 250.
00:59:11The shockingly beautiful Akrapovich exhaust system, which just...
00:59:19I did want to sit in an art museum and stared at a painting for a course I was taking.
00:59:26But I've not done that otherwise, but I would stare at Akrapovich exhaust systems.
00:59:34Yeah, my appreciation is deepened every time I try to make my own exhaust parts and...
00:59:42Oh, it's terrible in front.
00:59:43Oh, you know, you try to cut, you know, try to cut on the radius so that you get a...
00:59:47You need the hole to stay around. So if you cut it at an angle,
00:59:50you can't take your bend and connect it to your straight pipe. And so it's very...
00:59:55This is all very artisanal. Like I'm a guy with a bandsaw and a TIG torch and some tape measures
01:00:01and,
01:00:02you know, calculate... Trying to do it perfectly.
01:00:04And writing it down, calculating. So this is a centerline four-inch radius bend,
01:00:09meaning that if it's a three-inch pipe, then it's a four-inch radius. So the outer radius is
01:00:15four plus 1.5 and then it's four minus 1.5 to the inside. And then you take your seamstress
01:00:21tape
01:00:22and you go on the outside radius and then you do your pi r squared and you convert your degrees
01:00:27into inches and you try to make perfection. And then you look, what does the factory must look like
01:00:35at Kravavich? I can't even imagine because it comes out so immaculate and so perfect.
01:00:43And it's also tuned. It's not just beautiful. It's actually tuned for function. And that, to me,
01:00:51that's like where the beauty is truly informed because there are plenty of incredible fabricators
01:00:56who build beautiful exhaust systems that are not tuned for the engine. They just look great and
01:01:03they function well, but they're not actually filling in a mid-range hole, broadening power,
01:01:09increasing peak. It just looks good and it probably runs cooler. It runs cooler than an iron manifold on
01:01:15a car or, you know, it's a stock. Actually, stock systems are pretty darn good now. But I have to
01:01:22finish my sentence. Oh, sorry. I just remembered it. As usual. As usual. The one about the 1100cc V4.
01:01:32Yes. That engine with its intake system on it, they say weighs 143 pounds.
01:01:43That's less than the 200-something of the sit-up superbikes, which were also 1000cc engines.
01:01:51Now, of course, you could go into lots of detail. Those early superbikes had iron-linered cylinders.
01:01:58Well, that was great because that way, the older fellows who were accustomed to boring their
01:02:04triumph for new pistons every 10 or 15,000 miles could bore and refit.
01:02:11But it turns out that an engine that is well-managed by an ECU that is correctly programmed
01:02:19doesn't overheat. It doesn't do all the things that caused
01:02:26unbearable cylinder wear.
01:02:28Yeah. Well, nickel, silicon carbide too, by the way.
01:02:32Oils, yes. It's hard to wear out silicon carbide. Oils that don't allow as much
01:02:41of the terrible wear that mostly occurs at cold start.
01:02:47And I must say that I am the grandson of a man who worked for the state of Indiana.
01:02:52Indiana. He was a highway engineer, and he didn't understand automobiles at all.
01:02:59And I remember hearing him when I was a little boy. He had a 49 Ford, I think,
01:03:08that they issued him. And I hear the engine crank, and then he would just floor it.
01:03:13Well, he said, if I don't do that, it's just, it quits.
01:03:18Yeah, but, geez, cruelty.
01:03:22Yeah.
01:03:24Needless cruelty.
01:03:26Well, now we have additives in the oil that provide solid lubricant protection against cold
01:03:40starting, accelerated wear from cold starting.
01:03:44Yeah.
01:03:49So, there's, you know, the closer you look, the more details you find.
01:03:54Yeah. And I think one important distinction here is that we're talking about the Kawasaki,
01:03:59a highly developed race engine, making 150 horsepower for, I don't know, some period of time,
01:04:05but maybe not 50,000 miles.
01:04:07No, probably not.
01:04:08Right? You know, Rob, even Rob Muzzy would admit that it wouldn't, you know, wouldn't go,
01:04:13if you hammered it, it wouldn't go that far.
01:04:15And the Ducati, you know, I mean, we're talking about the Super Leggera Centenario,
01:04:20so the next generation before that is, we assume the next generation before that's debuted in the
01:04:25new Super Leggera Ducati. There's a podcast that we've done on that where we talk about all the
01:04:30tech, but that's a, I mean, that's a highly developed race-inspired street engine that is
01:04:36really a race engine for the street, but nickel, silicon, carbide, EFI, everything is precise and
01:04:43beautiful, and it would go a long time. And that's a street engine. That's where we're getting,
01:04:49you know, MotoGP, ah, 300 horsepower, et cetera. You know? Yeah, maybe. I would,
01:04:55wouldn't we just like to get one on the dyno here? I just, I got a dyno in the garage,
01:05:00guys.
01:05:01Bring me, bring me a MotoGP bike. Let's go. We'll tie it down real good.
01:05:06That's right.
01:05:07Might have to have pump extra air. I didn't think about that.
01:05:10Well, in the, in the old days of, uh, GP racing, um, one of the,
01:05:19bull taco riders, of course, was, uh, Ginger Molloy and Ginger Molloy knew everyone.
01:05:28And if someone at bull taco or wherever was curious about Suzuki's new one 25,
01:05:38he might under certain circumstances be able to prevail upon whoever was in charge of the parts
01:05:46truck. Because if nobody knows the thing is missing for a day and a half,
01:05:51it isn't missing for a day and a half.
01:05:55And so information was disseminated in a way that, uh, almost seems to foretell
01:06:02the internet, which brings us lots of information, not all of which is true.
01:06:09Um, signal the noise, signal the noise ratio.
01:06:13To separate the wheat from the chaff. Yes, sir.
01:06:17So, um, like I said, there's,
01:06:22there's so many details of things that have changed between 1982 and the present day
01:06:28in the building of high performance motorcycle engines.
01:06:32But these are the, the basics.
01:06:36Double the RPM, improved manufacturing.
01:06:39We have, we went through, uh, material improvements, design improvements, better crankshafts,
01:06:47uh, incredible connecting rods, much lighter pistons, valve area for days,
01:06:55camshafts and valve control mechanisms because the valves are lighter, but also vacuum remelted steel.
01:07:02Or in the case of Ducati using, uh, ever improving desmodromic valve operation where
01:07:08we really don't have springs. We have cams to close them very precisely
01:07:11and lay them gently upon the seat so they don't hammer.
01:07:15Lay them gently.
01:07:17And, uh, well, that's the thing is that, you know, you, you have to get it moving.
01:07:21So it, it, uh, it opens into the cylinder and then it's got to close.
01:07:25So when it's opening into the cylinder, it's got to go, uh, it can't, you can't hit it with a
01:07:32hammer.
01:07:32It's got to be just rapid enough to not harm the parts.
01:07:38And then once it's moving, yeah, let's get her open.
01:07:40But wait, we better slow down because we don't want to throw that valve all the way through the piston.
01:07:45So just, uh, it's exquisite, but yeah.
01:07:49When I talked to the guys at Dell West some, some 20 years ago, they told me that valve
01:07:58accelerations of 3000 G were, um, common with pneumatic springs.
01:08:05And of course in MotoGP, I think Suzuki was the first to adopt pneumatic springs around 2006,
01:08:13but they had passed through a period where they were changing valve springs every night.
01:08:18And anyone who goes to drag racing knows that in some cases they're changing the springs after every run.
01:08:27So it just depends on how hard you're working at steel.
01:08:31Dell West.
01:08:32And eventually you get to a point where you can no longer predict whether the, the valve
01:08:38spring will complete the necessary service.
01:08:42Then you need something that does not fatigue crack.
01:08:46Fortunately for us, air breathing creatures, air does not fatigue crack.
01:08:53So, uh,
01:08:57there's nothing mysterious about pneumatic springs.
01:09:00They're just gas pressure in place of spring pressure.
01:09:05And there's a lot of, as there always are niggly little details, which must be attended to, or the,
01:09:11the, uh, pressure cavity will fill up with oil or all kinds of bad, bad stuff happens.
01:09:19Yeah.
01:09:19They need to maintain the pressure in those chambers.
01:09:21So, you know, yeah, they, they have this little, this little unit on casters and they wheel it up to
01:09:29each bike and turn.
01:09:30And they, they charge the pressure reservoir that supplies makeup pressure, um, to compensate for leakage.
01:09:41That may occur at 20,000 RPM.
01:09:46Well, I hadn't thought about the heat factor.
01:09:48I guess, is it cool?
01:09:50You know, because the heat's when you compress it, does it cool when it expands?
01:09:53I guess it's a self, it's a self, self-healing problem.
01:09:57Adiabatic.
01:09:58Yes.
01:10:00Pretty neat.
01:10:02And of course, there's the liquid cooling system to take the heat away if it.
01:10:06Yeah, of course.
01:10:07Becomes a problem.
01:10:11And here we are, the evolution of the super bike engine.
01:10:15So yeah, I mean, uh, Z1 to, uh, to what we have today, pretty remarkable evolution.
01:10:23Um, I guess we could talk about BMW super bikes cause that's a remarkably different evolution.
01:10:28Right.
01:10:28So we've talked about inline fours, which is, you know, I mean, we are using B fours also, but.
01:10:33You know, BMW started with the flat twin when they were once, once again, reinventing themselves.
01:10:38Uh, BMW has had a series of re in brand reinventions.
01:10:43We must remain relevant.
01:10:45We must seek new market segments just as many manufacturers do, but there's have been very
01:10:50public.
01:10:51So they had the flat twin 900 and they said, we're going super bike racing.
01:10:55They started with their seven fifties in early 72.
01:10:57You know, I'm like getting those bikes out.
01:10:59That's how Oodle cut his teeth.
01:11:00Oodle was working on those seven 50 twins.
01:11:04And then they got the 900 and Butler Smith said, oh, the super bike racing.
01:11:08Yeah, let's do that.
01:11:09And they use, they use that flat twin.
01:11:11And for a while it was a magic moment for them.
01:11:14And then they didn't think about it for a long time, but who would have thought in a
01:11:18sort of 2008, nine, that, that BMW would come out with an inline four super bike and that they
01:11:24would subsequently win some world super bike championships with it.
01:11:28Pretty neat.
01:11:28Yes.
01:11:29That they just, they said, we are a traditional company.
01:11:32And that part of that equation is over here in this branding box.
01:11:36And now we're going to start this new branding box and, uh, the inline fours are usually top
01:11:41three, uh, in the selling proposition for BMW in terms of volume.
01:11:47So check the success box there, folks.
01:11:50Yes, we'd like it.
01:11:52The GS still rules the roost.
01:11:57The 1300, the flat twin.
01:11:59Well, thanks for listening subscribers.
01:12:02Uh, we really appreciate it.
01:12:03Love, love having you here, share with your friends.
01:12:07Um, I read every comment in Patreon, uh, you can message us, et cetera.
01:12:12I have recorded a shop tour as promised.
01:12:15Kevin promises he will record a shop tour and I will get that edited and I'll show you
01:12:21just a quick, you know, few minutes in my shop.
01:12:23You can see all the machine tools and it's not a lot of square footage, but it works.
01:12:27It's motorcycle sized.
01:12:29I just moved my bandsaw in there that I just picked up.
01:12:31So I got to get rid of the valve machine, which I had high hopes for.
01:12:35I've got a beautiful quick way valve grinder and all the associated valve seat grinding cones
01:12:41and the valve seat grinding drill bitty thing and the pilots.
01:12:45I have all of that and I'm really not in cylinder head production.
01:12:48So the square footage is more important than me someday doing another valve job.
01:12:55So we're going to farm that out and I'm going to use my, my bandsaw.
01:12:58So anyway, stay tuned.
01:13:01Thanks for listening.
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